The lead locomotive assigned to the train was #4031, an EMD E8 originally manufactured in 1952. The E8 developed 2,250 horsepower (1,680 kW) from two 12 cylinder model 567B engines, each driving a generator to power the two traction motors on one truck.[3] During the run south from Chicago the #2 engine on #4031 failed and could not be repaired. After a crew change in Champaign, Illinois, the new crew observed the #2 engine respond to the throttle and concluded that it was operational again. South of Champaign the Illinois Central main line was double track with crossovers. As the train passed over one of these crossovers at Tonti #4031 derailed.[4]

#4031 was badly damaged in the derailment; #4109, immediately behind, caught fire and was destroyed. The rear two locomotives remained upright and suffered little damage. The lead baggage car and first five coaches were destroyed. The remaining eight cars suffered varying degrees of damage. Eleven people were killed and 163 were injured. Six of the eleven fatalities occurred when passengers were ejected through large side windows.[5] It was Amtrak's first fatal accident.[1]

The NTSB investigation found flat spots on the rear truck of #4031. Inspection of the tracks between Tonti and Effingham, Illinois, revealed markings where the wheels had slid instead of spun. Further investigation revealed that the truck's traction motor had seized prior to the accident, and that the wheels had probably locked at Effingham during a station stop. The locked wheels created a false flange. When the compromised wheel reached the switch at the crossover at Tonti it derailed.[6]

#4031 had made another run from Chicago to New Orleans on June 6. Engine #2 had failed on that trip as well and was shutdown in New Orleans. As an added precaution the reverser for the engine was locked in neutral for trip to Chicago. Shutting down the engine and locking the reverser in neutral had the effect of disabling the wheel slip indicator, which would notify the locomotive engineer that a wheel was slipping or sliding.[7] While #4031 was repaired in Chicago, the Illinois Central maintenance forces did not observe that the reverser was locked and did not realize that power was not being supplied to the rear truck.[8]

The NTSB found that the mechanical faults in Illinois Central locomotive #4031 caused the derailment. It recommended improvements in wheel-slip detection devices for locomotives and in pre-departure testing procedures. The NTSB also recommended that the Federal Railroad Administration (FRA) draft safety standards to address the ejection of passengers through windows in the event of accidents.[9][10]

^Between May 1, 1971, and November 14, 1971, when Amtrak issued a new timetable, all trains were officially nameless and used the numbers assigned by their previous operator. This train had been Illinois Central #1, the City of New Orleans. Amtrak replaced it with the Panama Limited in November.[1]